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What Exactly IS the Mercury Problem?. David Gay (217) 244-0462 dgay@uiuc.edu, http://nadp.sws.uiuc.edu. Goals for this Talk What is the Mercury problem? Where and When? Why?. What is the Mercury Problem?. Primarily A Health Concern. Neurological Disorders
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What Exactly IS the Mercury Problem? David Gay (217) 244-0462 dgay@uiuc.edu, http://nadp.sws.uiuc.edu
Goals for this Talk • What is the Mercury problem? • Where and When? • Why?
Primarily A Health Concern • Neurological Disorders • Persistent bioaccumulative neurotoxin • Large problem in children to about age 7 • Birth defects • learning disabilities • Problem in adults under certain conditions • Other Disorders: • Kidney disorders • Possible human carcinogen
Examples…. • Industry • “Mad Hatters” • With very high concentrations in water • 1960s Japan, daily fish consumption near industrial processing • Minimata, 111 deaths • Nigata, 120 deaths • 1970s, Iraq and contaminated grain • alkyl mercury fungicide seed mistakenly used to prepare bread • more than 6,500 Iraqis hospitalized with neurological symptoms • 459 died
Focus is typically…. • Children and fetuses • Neurotoxicity: have no blood-brain barrier to mercury • Kidney disease • Others have been mentioned (autism, etc.) • NHANES ≈ children with 5.8 ug/L, still unknown • Potentially pregnant Women who could pass on Hg to fetus CDC's National Health and Nutrition Examination Survey (NHANES)
Dry Deposition Wet Deposition Bacterial action (water and sediment) predatoryfish Bioaccumulation of methyl mercury Through Fall (wet+dry) Geologic Sources (soil, rock, base flow etc.) Litter Fall Hg Hg Hg Me-Mercury Concentration Methylation Small fish Zooplankton Water Body/pore water
So if Fish Are the Problem, then..Where is the problem?Which fish are the problem?
See EPA Mercury Site for your State/Nation www.epa.gov/mercury
4-8 meals per month 3 meals per month 2 meals per month 1 meal per month
Fish Repeatedly Mentioned • Shark • King Mackerel • Tilefish • Swordfish • Grouper • Limit tuna consumption
Federal Drug Administration Advise…… • Pregnant women and women of childbearing age • Limit consumption of shark and swordfish to 1/month, particularly during the 1st trimester. • Limit consumption other higher-concentration fish. • Others • Limit regular consumption of high concentration fish, such as shark and swordfish to about 7 ounces per week (about one serving). • For fish < 0.5 ppm Hg, regular consumption should be limited to about 14 ounces per week.
Total Deposition, In Summary • Atmospheric transport and deposition is the dominant pathway to most aquatic ecosystems. • Between 40 and 75% of the mercury input to lakes and streams is by wet deposition • probably less in the West, where dry deposition dominates. (Sorensen et al., 1997; Scherbatskoy et al., 1997; Lamborg et al., 1995; Mason et al., 1997; Landis and Keeler, 2002; Mercury 2006 Committee Statement) • “New” mercury is more likely converted to organic form than “old” mercury
Total Deposition is.. • Wet deposition + (good data) • Dry deposition + (very little data) • Litterfall + (very little data) • Throughfall + (very little data) • Methyl mercury deposition (very little data) • Geological input (very little data)
Modeled Dry Deposition Seigneur and others, ES&T, 2004, V38, 555-569
Oxidation (long lifetime) How Mercury is Wet Deposited? Hgp RGM RGM Hgo Hgo Hgp rainout Hgp RGM washout
1.4-1.8 ng/m3 Typical Atm. Mercury Species Abundance Atmospheric Mercury Species Abundance Hg0 – Elemental Mercury RGM – Reactive Gaseous Mercury Hgp – Particulate Bound Mercury
Coal combustion Incineration Medical Trash Cremation Industrial emissions (chlor-alkali) Cement production (Hg in lime) Mining Hg use in gold and silver mining (amalgam formation) Mining for Hg taconite Automobile Recycling Mercury in Landfills Fluorescent lamps dental amalgams (also in sewers) Thermometers Batteries Discarded electrical switches Others will surface Other carbon fossil fuels (gas/oil/diesel)? Sources of Mercury • Volcanoes (St. Helens) • Naturally enriched ores/soils • Plate tectonic boundaries • Cinnabar (HgS), taconite, others • Soils and rocks (0.08 to 0.5 ppm in crust) • Evaporation • Soils • Fresh water and OCEANS • Natural forest fires • Tree bark (wood fire places) • soils • Volatilization from rocks? • Wind Blown reintroduction • Mine tailings • Industrial contaminated soils • Evolving Gases • Mines, industrial areas • Waste facilities (municipal in particular) • Out of soil
Mercury Deposition Network • A Cooperative Research Program • Part of National Atmospheric Deposition Network • 109 sites • Federal, State, Local and Tribal governments members, private organizations • Measuring wet deposition of mercury
NADP’s Goal • To monitor the chemistry of precipitation (rain and snow) consistently and as accurately as we can, for long periods to determine changes over time (trends).
Tribal Organizations Yurok Tribe; Sac and Fox Nation; Pennobscot; Grand Traverse Band of Ottowa & Chippewa Indians; Mille Lacs Band of Ojibwe; Akwesasne Mohawk Tribe; Cheyenne River Sioux Tribe; Makah Nation; Quinault Indian Nation
Mercury Deposition Network (MDN) Collects one-week precipitation-only samples with MDN wet-dry collector Measures precipitation with gage Analyses Total Mercury Methyl Mercury
NADP’s Plan: A Working Group FormedEric Presto NADP Vice-Chair - TekranMartin Risch NADP NOS Chair - USGSDavid Schmeltz EPA Clean Air Markets Div.Tim Sharac EPA Clean Air Markets Div.David Gay NADP-MDN Coordinator Review scientific methods for measuring or estimating dry deposition of mercury, Determine if these methods can be formalized into a network operation, and Develop the Network Plan (currently here) Present this network plan for NADP acceptance.
For more information David Gay, NADP dgay@uiuc.edu 217.244.0462 http://nadpweb.sws.uiuc.edu/amn/
What Exactly IS the Mercury Problem? David Gay (217) 244-0462 dgay@uiuc.edu, http://nadp.sws.uiuc.edu